This invention relates to power locks for sliding doors and the like, and more particularly, to a power operated lock assembly utilizing a reciprocal bolt for movement into and out of the path of movement of the door.
Sliding doors are very popular for all types of homes. In the modern home, it is not uncommon to find two or more sliding doors, especially in living areas of the home, such as opening onto a porch, patio, balcony or carport. A sliding door provides many advantages including ease of operation, large glazing areas for admission of light into the home and a wide passage for ease of entry and exit through the doorway.
The only shortcoming of sliding doors that has kept the door from being even more popular than it is, is the matter of security when locked. In the past, the sliding door has been subject to criticism from security officers for the lack of security locking means. In an attempt to fill the gap, various make-shift arrangements have been provided by homeowners, such as a wooden stick laying in the track of the door to jam the door against movement toward the open position. However, such an arrangement is very inconvenient and generally unsightly. The stick is prone to be misplaced while the door is open and provides a particular hazard for small children who will play with the stick. When the stick is removed, the door is left open and subject to unauthorized entry. Sliding door manufacturers do provide a lock at the forward jamb of the door, but the lock is very fragile and can be easily broken by insertion of a crow bar or other prying tool. The lock is also usually positioned by the manufacturer very close to the jamb so that operation of the lock is difficult without hitting the knuckles against the sharp edges of the door jamb.
Also, although power operated doors and windows have been in use for several years, insofar as I am aware, there has not been a power operated lock suitable for a sliding door. Locks adapted for automobile doors and other types of swinging doors are simply not adaptable to a sliding door arrangement where special problems of positioning of the components, strength required and ease of operation are present. For this reason, new locks in the field have been limited to purely mechanical locks of the type requiring direct engagement with the components of the lock in order to operate it. The mechanical locks are not adapted for remote control and thus do not provide convenience for the homeowner. Two typical prior lock arrangements are shown in the patents to Buck et al U.S. Pat. No. 3,768,847 (a simple sliding bolt utilized with a manually operated mechanical release button required to be pushed to unlock the door) and the Stevens U.S. Pat. No. 4,248,461 (a manually operated pivoting lever having a plurality of notches for engagement with a plate).
Another manually operable bolt lock (similar to the Buck patent '847) is shown in U.S. Pat. No. 3,082,617 to Kerman. A key-actuated closure lock has a bolt which enters a recess in the closure sash to prevent movement of the sash. This lock cannot be actuated from outside the closure.
U.S. Pat. No. 3,950,018 to Pickering discloses a very complicated locking device for railway freight car or other freight vehicle doors. The lock, which is built into the freight car door, is provided with a movable bolt which enters a recess in the doorway to prevent opening of the door. The lock may be opened by the use of compressed gas, by a solenoid or by the use of a key used in conjunction with the compressed gas. This massive lock, which is built into the heavy freight car door, cannot be used with a door such as a sliding glass door.
U.S. Pat. No. 4,141,610 to Ando discloses a showcase lock wherein the armature of a solenoid extends into a recess in the glass showcase door to lock this door whenever it is in the closed position. Unless the solenoids are continuously energized, the doors will be locked at all times when the doors are closed. This would be totally unsuitable for use, for example, with a sliding glass door opening onto a patio or deck.
U.S. Pat. No. 2,765,648 to Hatcher discloses an electro-magnetic vehicle door lock actuated by two solenoids. One of the solenoids is energized to unlock the door and the other is energized to lock the door. The structure of this lock is unsuitable for a sliding glass door and the use of two solenoids requires an unduly complicated control circuit.
Thus, the need is present for an effective power operated lock for a sliding closure, such as a sliding door for a home.
With this in mind, it is an object of this invention to provide a power operated lock for a sliding door which overcomes the problems present in known locks.
It is another object of this invention to provide a power operated lock for a sliding door which can be operated for opening from either the inside or outside and which can also be manually operated.
It is a still further object of this invention to provide a power lock which is simple in construction and inexpensive to manufacture, yet has exceptional strength so that the door cannot be pried open.
It is still another object of the present invention to provide a power door lock assembly with power operation and including cooperative parts that are easy to engage to provide the locking and unlocking functions.
Still another object of this invention is to provide a power operated lock that is easy to set and includes visual indicating means allowing the user to determine at a glance whether the lock is set in a locked condition.
Additional objects, advantages and other novel features of the invention will be set forth in part in the description that follows and in part will become apparent to those skilled in the art upon examination of the following, or may be learned with practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.